This invention relates to a ground plane for a plurality of associated electrical conductors with the ground plane comprising a plurality of isolated segments to provide alternate conductors having a lower impedance than the associated plurality of conductors. More specifically, the present invention relates to a ground plane for a plurality of conductors coupled to an electrical device such as an integrated circuit, wherein the ground plane contains a plurality of isolated portions that provide lower impedance conductive paths to the integrated circuit.
As the complexity of electrical devices such as integrated circuits increase, while the size of the components thereon correspondingly decreases, the number of electrical conductors or leads connected or coupled to the integrated circuit to enable operation of the integrated circuit increase in number and correspondingly decrease in size. For example, at this time it is very common that an integrated circuit will have hundreds of conductors or leads connected thereto and typically these are no more than about one-half mil thick, about two mils in width, with about two mils spacing therebetween. These small conductors have a considerable impedance such that a significant voltage drop takes place along the length of the conductors that supply operating power to the integrated circuit. Further, variations of the DC operating current creates switching noise due to the high impedance of these conductors. Additionally, the capacitive coupling between these conductors causes cross talk on the signal lines going to and from the integrated circuit. Heretofore in the prior art a ground plane associated with the plurality of conductors has been used to reduce the capacitive coupling between the conductors to reduce cross talk on the signal lines. This ground plane has also been used as a conductor for one side of the DC supply used to power the integrated circuit.